Medical devices are frequently used to treat the anatomy of patients. Such devices can be permanently or semi-permanently implanted in the anatomy to provide treatment to the patient. Frequently, these devices, including stents, grafts, stent-grafts, filters, valves, occluders, markers, mapping devices, therapeutic agent delivery devices, prostheses, pumps, bandages, and other endoluminal and implantable devices, are inserted into the body at an insertion point and delivered to a treatment site using a catheter. Common types of expandable devices include stents and stent-grafts.
Expandable devices such as stents or stent-grafts are used in a variety of places in the human body to repair aneurysms and to support various anatomical lumens, such as blood vessels, respiratory ducts, gastrointestinal ducts, and the like. Expandable devices can have a reduced diameter when in a collapsed configuration, and can be designed to spontaneously dilate (i.e., elastically recover), or be balloon-expanded, from their collapse configuration, through one or more intermediate configurations, up to a maximum functional configuration. Expandable devices can be constrained in the collapsed configuration with a sleeve to facilitate transport to the treatment site.
The endoluminal delivery and deployment of expandable devices pose potential issues. First, the expandable device itself must be radially compacted to a suitable delivery configuration to allow insertion into the vasculature, constrained and mounted onto a delivery device such as a catheter. Subsequently, the constraint must be removed in order to allow the expandable device to expand or be expanded to its functional configuration and achieve the desired therapeutic outcome. A variety of ways of constraining and deploying an expandable device are known in the art. For example, an expandable device can be constrained by one or more sleeves with deployment comprising the removal of the one or more sleeves.
As such, there is an ongoing need to improve the endoluminal delivery and deployment of expandable devices such as stents and stent-grafts. New devices, assemblies and methods of deployment that can improve the use of sleeve-constrained expandable implants would be useful and desirable.